Oil gasification process



June 2, 1936. A. JoHNsoN 20429999 OIL GASIFICATION PROCESS Filed Aug.24, 1952 2 Sheets-Shet l III Emme 2, i936. A. JOHNSON 2,042,999 n OILGAS IFICATION PROCESS Filed Aug. 24, 1952 2 sheets-sheet 2 STEHMPatented .lune 2, 1936 V l UNITED STATES PATENToFPlcr.

OIL GASIFICATION PROCESS Alfred Johnson, West New Brighton, N. Y., as-

signor to Combustion Utilities Corporation, New York, N. Y., acorporation of Maine Application August 24, 1932, Serial No. 630,176 InCanada August 16, 1932 2 Claims. Cl. 48-214) This invention relates tooil gasification, andA secondary air entering the carbureter, due tomore particularly it concerns a process and apsuch factors as unsuitablylow velocity ow of the paratus for the uniform production fromhydroblast gases to the carbureter, and the lack of suitcarbon oils andgases of a combustible gas of able equipment for properly mixing the gasand 5 regulated heating value and specific gravity, secondary air in thetop of the carbureter. 5 adapted as a. substitute for natural gas ormanu- In certain instances it sometimes happens that factured gas foruse for industrial and domesthe top of the carbureter becomessocooledduring tic purposes. The invention has special utility the sprayingthereto of oil in the carbureting step in connection lwith a process andapparatus of of the gas-making cycle, particularly where a the typedescribed in my co-pending patent apvery large amount of carbureting uidmust be l0 plication, Serial No. 561,354, led September 5th, employedfor enrichment purposes,that the 1931 for Oil gasification process andapparatus, rst portion of the blast gases owing to the involving thespraying of oil upon a highly heatcarbureter upon the succeeding heatingcycle, is ed refractory generator screen after the latter notimmediately ignited in the carbureter top.

l5 has been heated uniformly to gas-making tem- Such ignition may thenoccur explosvely further l5 perature by consecutive up-and-down airblastalong in the-carbureter or superheater,and of ing in successivestages of a heating cycle,the course is highly objectionable for obviousreasons. heat for the oil gasification being supplied by These variousundesirable conditions may incombustion alone of the carbon depositedwithin terfere to some extent with the uniform eilicient the generatorscreen during a previous gas-makoperation of the gas-making set. 20

ing cycle. The invention however is not limited The present invention isbased upon the disto such application, but is also of distinct valuecovery that the diiculty in such cases in obtainin various oilgasication processes involving the lng sumcieut heat for all carburetionpurposes in enrichment of a primary combustible gas within theproduction of a relatively high heating value a carbureter element. gas,such as e. 75o to 1200 B. t. u. gas, is due to 25 F01 purposes 0fillustration only. the inventiOn the dimculty sometimes encountered incertain is here described in connection with an oil gasicarburetedwater-gas sets in properly burning the cation 91706655, utilizing 8-refrlCtOry Screen type primary blast gases and free carbon with secfgenerator, in View 0f its Special application to ondary air in the upperpart of the carbureter this type of operation. during the heating orblast cycle. Ample carbon 30 In processes of the type set out in myabovein all cases is provided within the refractory genmentllied(20-Pending applicalOn. preferably the yerator screen in theafore-mentioned Johnson all' OW rates during the air blasting Or heatingoil gasication process for supplying all the heat cycle are sufllcientlyhigh to produce a substanrequirements for preparing the set for asubsetial amount of turbulence in the blast gases, and quent gasmakingcycle. Applicant has further 35 to effect an intimate mixture thereofwith the discovered that in instances where the design of secondary airintroduced therewith into the unthe gas-making set is such as to preventtherein Per Dart 0f the generator and/or carbureter. suiliciently highgas velocities, and where the lack This mixing is greatly facilitated bya tangential of other conditions producing turbulence and in- 40arrangement of the blast gw inlet line to the tlmate intermixture ofblast gases and secondary 40 carbureter. Under such conditions all oftheblast air in the carbureter top prevents sufficiently gases are veryrapidly and completely burned rapid and complete combustion therein,theset Within the lOl) 0f the carbureter 01' PIlOI lhelecan still functioneffectively for oil gasification tof-wgether with CarbOn which may bemechanemploying a refractory screen generator and sucically carried overwith the blast gases from the eessive up-and-down blast stages in aheating 45 refl'aCtOry genera-t0? Sore-em cycle by providing for theburning during either In the case of some installatlons,.however, parorboth stages of the blastcycle of very small tlculally WherePreviOIlSlY-CODSCI'UCJC Standard amounts of hydrocarbon oil or gas inthe toplof water gas set-S have been modied for the practhe carbureteror alternatively, in the top of the 30 tice of the invention describedin the afore-mengenerator. By burning as small an amount as 50 tionedJohnson application,-the arrangement, from .1 to .8 gallon of gas oil orfuel oil in the top and construction of the generator and carbureter ofthe carbureter during the blast cycle per. 1000 with their connectionsis such that under normal cubic feet of gas made, a wide variety oftypes of conditions ofoperation there is an insufcient standardcarbureted water gas sets may be readily or improper mixing of the blastgases with the adapted for producing gas varying in heat value 55 willvary primarily with the amount of carbureting oil required to bring theheating value of the gas up to the desired amount, but also somewhat inaccordance with the specific design of generator, carbureter andconnections, and the rates of gas flow possible through the variousunits of the set. Within reasonable limits, the larger the combustionspace provided in the top of the carbureter and the more intimately theblast gas and secondary air are mixed, the smaller the amount of oilrequired'to be burned during the blast cycle in the top of the generatoror carbureter for supplemental heating purposes.

In the accompanying drawings illustrating certain preferred apparatusforming part of the invention, Fig. 1 shows in vertical section asomewhat modified standard water gas set; and Fig. 2 shows in verticalsection a four-unit gas-making set embodying the invention.

- Referring to Fig. l, numeral I 0 designates a gas generator connectedthrough conduit I2 with a carbureter I4. The latter is connected at itsbase with a superheater I6, from which a 4conduit I8 controlled by valveI9, leads to a wash box 20,-with the latter of which the usual gasoitake line 22 communicates and leads to gas scrubbers and to storage.vThe superheater is provided with the stack valve 26.

The generator I0 has therein a grate 28 upon which is supported a gaspermeable bed or screen of considerable depth, composed of refractorybodies, which may if desired be impregnated or mixed with high-meltingoxidation-resistant metals or alloys such as nickel or platinum. Thedepth of the screen will vary from around 2 feet upwardly, dependingupon the nature and size of the refractory material; and upon suchconditions of operation as the temperatures to be maintained in thescreen and the rate oi flow of gases therethrough. While the size andshape of the refractory bodies employed in the screen may vary somewhat,highly satisfactory results have been obtained employing `a depth offrom 21/2 feet to 6 feet of `refractory bodies each approximately 11/2"x 11/2.' x 11A.

in size. The uppermost layers of refractory bodies forming the screenmay be of somewhat smaller size than tho'se in the lower portion of thescreen; and the bodies may be oblong or round in form. Round refractorybodies are of particular advantage in the upper layers of the refractoryscreen because this shape gives -a more uniform distribution of the openspace be-` tween adjacent bodies and thereby forms a screen having moreefllcient filtering action.

Since temperatures as high as 2600 to 3000 F. sometimes are developed inthe refractory screen, the material composing the refractory screenpreferably is of highly heat-refractory material. High aluminarefractories such as Alusite (which is a 60% aluminum oxide refractoryhaving a low iron content and embodying a coarsely ground aggregateburned to a high temperature) are serviceable,-as are refractories made.from carborundum, pure alundum, and high silica bricks, which areadapted to resist temperatures well above 3000 F. vfor long periods oftime without injury.

The lower part of the generator I0 below the grate communicates with theconduit 'I2 through the line 32 controlled by valve 34. A .valve 36 isdisposed in the line4 I2 between the generator and line 32.

For introducing air for combustion into the generator and carbureter, avalve-controlled air header 31 is in communication with the gener- 5ator below the grate through conduits 33 and 42 under control of valve46-and with the generator above the refractory screen through conduits38 and 48 controlled by valve 50. A branch line 40, controlled by valve52 leads to conduit I2 at lo or adjacent the carbureter. For the purposeof supplying steam to the various elements of the gas-making set.,there'is provided a main steam header 54, having branch line 56controlled by valve 58, communicating with the base of the l5 generator;and steam line 60 controlled by valve 62 leading to the upper end of thesuperheater.

A branch steam line 64 controlled by valve 66 controls the iiowof steamto the top of generator III-as required. A steam line 68 connects theline 64 through the valve-controlled branch lines 10 and 12 with the oilspray nozzles 14,

, 16 in the generator and carbureter. Each spray nozzle' is providedwith a cooling jacket and with means including inlet and outlet waterconnec-A 25 tions 18 and 19. Valve-controlled oil lines 80 and 8|communicate respectively with the spray nozzles 14 land 16. A rich gasofftake header 82 controlled by valve 84 establishes communicationbetween the lower part of the generator 30 below the gra'te and the washbox through valved connection 85. A branch rich gas oiftake 88controlled by valve 88 leads from the generator above the refractoryscreen therein to the header 82. The base of the generator below thegrate is in valve-controlled communication with a stack i60 throughconduit ISI controlled by valve |62. A valve-controlled blast gasconduit |64 may connect the conduit IGI with a waste heat boiler forheat regeneration.

For the purpose of heating the various ele-- ments of the gas-making setincluding the refractory screen, when starting up, a valve-controlledoil conduit 94 leads to the generator below the grate,-and avalve-controlled oil conduit 96 leads to the generator above the top ofthe refractory screen therein. Furthermore a fluid fuel burner 89, whichmay include a valvecontrolled fluid fuel supply line 92 and avalvecontrolled air supply line 90 is disposed in the upper part of thecarbureter. A valve-controlled air conduit 99 leads to the top of thesuperheater I6.

In the modification of the invention illustrated in Fig. 2, therespective generator and carbureter are of somewhat different designthan in the corresponding units of Fig. 1. The i'eatures of constructionshown in Fig. 2 are similar to those of Fig. 1, with certain exceptionsindicated b'e- 60 low:

'The header |32 is connected through the valvecontrolled line |34 withthe upper part of the carbureter; and through the valve-controlled.conduit 4|36 with the upper part of the regen- 75,

|| 0. A rich gas offtake conduit |20, controlled by the valve |22,establishes controlled communication between the base of 4theregenerator |00 and the wash box. A valve-controlled air conduit |38 isconnected with the lower part of the regenerator |00. Both the base andthe upper part of the generator are respectively connected with the washbox by way of rich gas conduit |20 and Iinterconnected conduits |24 and|26, controlled by the corresponding valves |28 and |30.

In the practice of the invention using the water gas set shown in Fig.1,-a series of cycles including the following preferably is employed,although the respective up-blast and down-blast stages may beinterchanged if desired. Assuming that the various elements of the setare at Working temperature, and that an oil gas-making cycle has beencompleted and the refractory screen contains carbon deposited in andupon it, a small amount of a hydrocarbon uid, oil or gas, and air,preferably premixed, is introduced in the top of the carbureter throughconduits 92, 90 and burned therein,-the heat therein igniting thecombustible mixture. The resultant combustion gases highly heat thecarbureter top, and then flow through the carbureter and superheater.

The necessary valves are adjusted to cause a flow of air alone, or ofair more or less saturated with steam into the generator through conduit42. The air flows upwardly throughu the highly heated refractory screenand reacts with the carbon held therein. The resultant blast gasescarrying more or less carbon inl suspension then ilow to the carbureterwhere they are promptly ignited by the burning oil therein and areburned with secondary air introduced at 40. The checker brick of thecarbureter and superheater are thus readily brought to temperaturespreferably in the range from 1350 to 1500 F. After the up-blast airstage is continued for suilcient time to burn the carbon from the lowerpart of the generator screen, the valve 46 is closed, and a shortdown-steam purge of the generator is effected by steam flowing from line64, the purged gases flowing through line 32. Then valve 50 is opened toadmit-air to the generator above the refractory screen, and theremaining carbon thereinis burned by air flowing downwardlytherethrough; the blast gases flowing through conduit 32 to thecarbureter where they are burned with secondary air. During' thisblasting stage the burning of oil in the carbureter top preferably iscontinued, although in many cases this is not essential.

The carbureter oil burning preferably is discontinued a short time inadvance of the termination of the second air-blasting stage, and in anyevent before the succeeding gas-making cycle begins.

After the major portion at least of the carbon in the generator screenhas been consumed, and the latter brought to suitable gas-makingtemperature, the ow of` air is discontinued, and a short down-steampurge is effected by steam flowing from line 64; the resultant purgedgases flowing through the carbureter and superheater to the wash box. Amixture of steam and hydrocarbon oil is then introduced intothegenerator through nozzle 14, supplemented if desired by steam flowingfrom line 64. The nozzle effects thorough oil distribution upon the topsurface of the generator screen, and rapiddecomposition of the oiloccurs. The mixed hydrocarbon gases and water gas formed during passageof the oil vapors and steam through the refractory screen flow to thecarbureter where they encounter a spray of hydrocarbon oil or othercarburant; and the carbureted mixed gases flow through the carbureterand superheater to the wash box.

The oil introduced into the carbureter through nozzle 16 preferably isof a lighter gravity than that employed in the generator,.-such as gasoil. It is preferred to use in the generator a heavier hydrocarbon oilsuch as one having an A. P. I. gravity of 12|J to 181/2, ora hydrocarbonmixture containing the tar produced in the process which is well adaptedfor use in the present invention.

Following completion of the down-run cycle, an up-run with steam isemployed, the latter being introduced through conduit 56, and theresultant mixed gases flowing through the carbureter and superheatereither with or without enrichment, and thence to the wash box. Theabovementioned series of cycles is then repeated.

The efficiency of the process is greatly improved where the primary airand/or secondary air employed is preheated to or near the ignitiontemperature of the carbon deposited in the generator The Aheat requiredfor preheating the air may effectively be that regenerated from theprocess. In such case the previously described procedure is then modiedin the following manners-The air, with or without admixture with steam,employed in the second or `down-blast stage of the air blasting cycleenters the superheater through conduit 99 and thence ows to thegenerator, being heated during passage through ,the superheater andcarbureter. The preheated air flows downward through the refractorygenerator screen and thence through the stack to the atmosphere. Duringthis stage of the heating cycle the carbureter oil burner 89 preferablyis cut oif. Additional cold or preheated air can be introduced throughline 40 to the gases entering the generator during this stage.

In the preferred practice of the invention employing the constructionshown in Fig. 2, the series of cycles are the same as those describedabove, with the exception of the up-blast cycle. In the latter, theblast gases owing from the generator screen are divided and a selectedpory tion thereof flows to thecarbureter and superheater in themannerpreviously'described. During this stage oil or hydrocarbon vapor or gas1s burned with air in the top of the carbureter in regulated amounts forthe purpose of bringing the carbureter top to the desired temperaturefor supporting enrichment of the gases produced in the succeedinggas-making cycle. A second regulated portion of the hot blast gases fromthe generator flow directly through the regenerator |00 to the stack||0. In instances where it is desired to increase the temperature of theblast gases leaving the generator a small amount of oil may beintroduced into the generator through line 96 and burned therein withair introduced through line 48, the superheated gases then owing to therespective regenerator and carbureter. The burner 95 may be used 'aloneor in conjunction with the carbureter burner 92 during this stage of theblast cycle.

The heat recovered in the regenerator I from these blast gases is usedfor preheating 4air and superheating steam subsequently used in theprocess. The steam enters the regenerator s through conduitl |04, thenceflowing tangentially into and downwardly through the generator with theoil spray or oil-steam spray introduced through nozzle 14.

'I'he preheated blast air in either the up-blast or down-'blast stagemay be tempered and the oxygen content augmented by cold or preheatedair introduced to the generator through conduitsv 2li-introduced intothe superheater through conduit 60. No carburant is introduced into thecarbureter during this stage of operation. The mixed steam andcombustible gases are directed either upwardly or downwardly through thegenerator "screen, as desired, and the resultant combustible gases flowto the wash box either from the base of the generator or through branchconduit l0,

by-passing' the carbureter and superheater.

The oil or mixed oil-gas-water-gas produced by the invention has acontrolled heating value resulting from combination of water gas, low B.t`. u-. gas, enriching gas and blow-run gas, within the range of fromaround 400 to 1200 B. t. u. per cubic foot, and a specific gravity offrom around .28 to 40 .70 or higher, depending upon the specificoperating conditions selected. A wide range of mixtures of oil withgaseous hydrocarbon such as reilnery cracking still gases mayeffectively be utilized. In one specific operation, .3 to .6 pounds ofsteam was employed during the down-run per pound of oil introduced intothe generator, the amount of steam varying with the desired gravity ofthe nal gas and the quality of oil employedadditional oil being employedfor enriching the mixed gases within the carbureter for producing a 1000B. t. u. gas. 'I'he upsteam nm required from .45 to .6 pounds of steamper pound of generator oil employed. Approximately 50% of the totalprimary blast air wasA utilized in the upblast stage of the heatingcycle, although the ratio of air owing throughA the refractory screen inthe respective stages may be substantially varied. Usually asomewhatdarger amount of air is used in the upblast stage than is usedin the down- 50 blast stage. Ratios as high as 3:2 have been ernployedsuccessfully in this operation. The total amount oi' air used in-theblast cycle preferably is in the range of from 32 to 45 cu. ft. perpound of oil fed to the generator. i

In instances where the down-blast stage is followed by a down-steampurge in which the purged gases flow to the carbureter and superheater,the carbureter 4heating burner is shut of! during the purge step.-

ilcation andlclaims is intended to designatel a filtering screen ofheat-resistant refractory bodies of'such size and shape,and the screenbeing of such depth.that suiilcient carbon formed by hydrocarbondecomposition is retained thereby The term refractory screenfused inthespeciduring a gas-making cycle to yield upon subsequent combustionsubstantially enough heat to supply the full heat requirements forcracking the hvdrocarbon oil in a'subsequent gas-making cycle,

and for at least approximately providing the total heat requirements forthe subsequent enrichment of the resultant gases'.

The auxiliary oil burner in the carbureter top supplies any heatdeficiency in the latter due to diiliculties in distribution of thesensible and potential heat of the carbon-carrying blast gases leavingthe generator screen. By igniting the carbureter oil burner prior tobeginning the primary up-blastv stage, the burner functions in thenature of a pilot light to insure ignition of the blast gases in thecarbureter top. The utilization of the carbureter heating-burner and thecombustion of a very small amount of "oil therein, makes possible theadjustment of velocity rates of'gas flow through-the generator screenbetween wide limits. It may be stated generally that high -gasvelocities, above 150 cubic feet of air lper square foot ofcross-section lof the refractory screen. are not sobenencially effectedby the burning of small amounts of oil in the carbureter, as are unitsdesigned for operation where the gas velocity through the refractoryscreen is below that mentioned.

In instances where blower equipment associated with 4standard water gasplants'give available pressure head of 40" of water or less, thevelocity of the blast gases flowing through the generator screen usuallyisbelow that necessary to bring over any substantial .amount .ofsuspended carbon from the generator and for proper mixing with secondaryair for heating the carbureter top.

In such instances, the combustion during one or both stages of the airblasting lcycle of from 1 to .8. gallon of gas oil or fuel oil, for eachlthousand cubic feet of combustible gas varying in heating.

value from 500 to 1200'B. t. u. per cu. ft.- and in gravity from .40 to80, produced in the operation, will render such gas-making set fully aseiilcient for carrying out the aforesaid process as where new equipmentis employed which has been designed for providing the necessary gasvelocities and intimacy' of mixing of blast gases with secondary air toeffect proper'distribution of heat within the top of the carbureter andadapt the latter properly to function for enrichment purposes during thesucceeding gas-making cycle.

It will be obvious to those skilled in the art that the presentinvention is not connned in its application to gas-making units in whichthe generator is in a separate housing from the carburet-v 1. In acyclic process for making combustible gas I wherein during a gas makeperiod hydrocarbons are cracked by passing the same through a relativelydeep carbon filtering screen of highly heated uniformly sized smallceramic pieceswithresultant production of hydrocarbon gas and depositionof carbonl on the surfaces of the ceramic which carbon is burned duringa subsequent air blast period, the step of blasting air successivelyupward- 1y and downwardly through the ceramic screen during the airblast period in amounts controlled to burn the carbon and heat theceramic to high gas-making temperatures with the production o! blastgases, burning the hot blast gases after admixture of secondary airtherewith, insuring ignition o! the air-,blast gas mixture andsuppleinenting the heat developed thereby by controlled combustion of areadily combustible iluid fuel supplied from an independent source to apoint in the path of the mixture, storing the heat thus developed duringthe blast cycle, and utilizing the thus stored heat in vaporizing oil tocarburet the gases produced during the make cycle. I

2. In a process of the type defined in claim 1, the employment as ailuid fuel for igniting the secondary air-blast gas mixture and forsupplementing the heat thereof, of from .1 to .8 gallons of readilycombustible liquid hydrocarbon for each 1000 cu. ft. of combustible gasof desired heating value and gravity produced in the gasmaking cycle.

c ALFRED JOHNSON.

CERTIFICATE or CORRECTION.

Patent No. 2,042,999. .nine 2, 19:56.

ALFRED JoENsoN.

It is hereby certified that error appears in the printed specificationof Y the above numbered patent requiring correction as follows: Page 2,second column, line 49, for the words "which may include" read havingassociated therewith; page 4, second column, line 42, for "80" read .80;and that the said Letters Patent should be read with these correctionstherein that the same may conform to the record of the case in thePatent Office.

Signed and sealed this 8th day of September, A. D. 1956.

Leslie Frazer (Seal)` ActngCommissioner of Patents.

